"People often prefer to use positive emotions as tools more than negative and tend to see negative emotions as undesirable and maladaptive," Lench said.

The researchers recorded a "significant" increase in the eye ring size of both sexes among pair-bonded partners throughout the experiment, a change that was not observed in single birds or those paired with non-preferred partners.

Science tells us that relationships are more important than ever – the key ingredient to our happiness, as important to our health as not smoking.

Confidence should be increased; pride should be reduced; opportunity should be taken; laziness should be eliminated.

Don't destroy anything until you're sure you can do better.

Try everything you haven't experienced, good or bad.